FOSS Java is good. Well FOSS-anything is good in my book :) But Java represents a huge contribute to user and developer freedom. I think FOSS Java will also mean that us ivory tower inhabitants can concentrate on improving Java in our own special way. I think the FOSS community (GTK and QT guys) will be able to help Sun get their GTK/QT backends for Java 1.6 up to the same standard as the Eclipse RCP.

It's also a huge boost to the Mono guys. A lot of their cool tech has been ported from Java (eg: lucene).

But now in FOSS web-development world we have
* Ruby on rails
* Python Django
* Mono/ASP.Net
* LAMP
* and now Java Struts.
I wonder how long it will take .Net developers to demand an OSS .Net? Sun didn't make Java OSS to please RMS, they did it because their developer community demanded it.